# Vesalius

> An on-device code graph for macOS that gives Claude Code and other MCP clients answers about a codebase through an MCP server, CLI, Mac app and VS Code extension.

Vesalius, made by Haplo, LLC, indexes a repository locally on a Mac and builds a code graph of how files, symbols and calls connect. It exposes that graph to Claude Code and other MCP clients through five read-only tools, and also ships a CLI, a Mac app and a VS Code extension. The latest release listed is v2.1.0.

## What It Is

Vesalius is a code-intelligence tool that reads a repository once and stores the result in a local SQLite index. Instead of an AI assistant chaining searches and file reads, it can ask Vesalius who calls a function, what a file contains, or where a feature lives, and get answers with file and line references. The README states that indexing runs on the Mac and that Vesalius itself does not upload code.

## The five MCP tools

- `usages`: callers and uses of a symbol or file, including type-inferred uses, with a completeness check and, for rename, signature or remove changes, an edit list and tests to run.
- `feature_map`: core types and functions for a feature question, grouped by role.
- `outline`: declarations, signatures and line ranges for a file, type or function.
- `architecture`: targets, packages, dependency direction and cycles.
- `dependency_cycles`: circular imports in scope.

The same queries are available from the terminal, along with commands such as ask, impact, health, hotspots, unused, map and watch.

## Setup path

Installation is via Homebrew followed by `vesalius setup`. Setup registers the MCP server with Claude Code (and Codex if installed), adds a permission rule for the read-only tools, and indexes the current repository. `vesalius setup --undo` reverses it, and `vesalius doctor` and `stats` check the connection and show what Claude asked. It requires a Mac with Apple silicon on macOS 15 or later. Cursor and other stdio MCP clients can be registered manually.

## Mac app and VS Code

The Mac app shows an overview, a clustered dependency system map, a health score with explained deductions, and plain-English ask. It can also run Claude Code or Codex on a finding in plan-only or edit mode. The VS Code extension adds health, current-file and hotspot views, Problems-panel findings, CodeLens, change-impact commands and MCP registration for agent mode.

## Benchmark and language support

The authors report a benchmark of 20 questions over 6 codebases in which Claude Code with Vesalius used a median 51% fewer tokens, with no measurable change in overall answer quality; answers about where a feature lives scored 2.1 points lower. Swift gets a full syntax-tree analysis. TypeScript, JavaScript and Python use tree-sitter. Other languages are read lexically without a call graph.

## Features
- Five read-only MCP tools: usages, feature_map, outline, architecture, dependency_cycles
- On-device SQLite code graph with incremental indexing
- Rename, signature and remove impact lists with tests to run
- Completeness checks on usage results
- CLI commands including ask, impact, health, hotspots, unused, map, query and watch
- Local usage stats and doctor diagnostics
- Mac app with overview, system map, health score and ask
- VS Code extension with CodeLens, Problems findings and change-impact commands
- Swift, TypeScript, JavaScript and Python reference analysis
- Reversible setup with dry-run option

## Integrations
Claude Code, Codex, Cursor, VS Code, Homebrew, MCP

## Platforms
WINDOWS, MACOS, LINUX, API, VSC_EXTENSION, CLI

## Pricing
Free

## Version
2.1.0

## Links
- Website: https://github.com/haplollc/Vesalius
- Documentation: https://github.com/haplollc/Vesalius/blob/main/docs/benchmark/README.md
- Repository: https://github.com/haplollc/Vesalius
- EveryDev.ai: https://www.everydev.ai/tools/vesalius